How to Build a Fire Pit With CMU Blocks

Build a concrete block fire pit in your yard.

A fire pit area adds an inviting ambiance to a yard. You can build your own concrete block pit from CMU blocks to create an outdoor gathering area that will provide enjoyment for years to come. The materials are relatively inexpensive and you can finish this project in just a few hours. You can do all the planning and construction for your fire pit project and be able to enjoy a cookout or cozy fire that same day.

1

Measure the area where you want to construct your home fire pit. Decide on the size, shape and height of the finished pit. Use chalk or tape to mark the area. Assess the marked area to be sure you have allowed room to keep the pit away from low hanging trees, outbuildings or decks, and that you have enough room to comfortably place chairs and small tables as you wish. Adjust the marked area, if needed.

2

Calculate whether to use CMU's that are 8 inches wide, 16 inches wide, or a combination of both sizes to create your fire pit. Choose the depth -- 4, 8, 12 or 16 inches -- of the blocks you want to use. Remember that the height for each unit is 8 inches when figuring how tall you want the finished pit to be.

3

Use a shovel to remove grass or soil inside the marked area. Dig about 4 inches below ground level to make a sturdy base with the first row of CMU's. Save the extra soil.

4

Push the first row of blocks firmly into the soil with the inside edges touching to form a round-shaped pit or the entire side edges touching for a square or rectangular shape. Use a level to check for a level surface all around. Shovel some loose soil around the inside of this row and press it firmly to hold the blocks in place.

5

Begin the second row, centering the blocks over the seam between two blocks in the first row. Continue placing rows on the pit edge, alternating the seams of each row to make the structure more sturdy.

6

Scoop gravel inside of the pit to cover the bare soil.

Things You Will Need

Tape measure

Chalk or tape

Shovel

Level

CMU blocks

Gravel

Landscaping flat blocks (optional)

Grate (optional)

Tips

Put a row of flat landscaping blocks on the top edge of the pit if you want. Fasten the flat blocks onto the edge with mortar.

Warnings

Use concrete mortar between the levels of blocks if the structure is higher than three 8-inch-tall CMU's.

Place a metal grate over the fire pit when burning wood to allow flames to come through, but prevent exploding wood or burning ashes from floating outside the pit and landing on objects or people.

About the Author

Larry Davis has worked in the safety and environmental field since 1975, writing for "Chevron Review" and other professional magazines. He wrote monthly columns for "Heavy Equipment News" and has written safety programs and training materials. He holds two bachelor's degrees, a master's degree in safety and earned his doctorate in safety engineering, studying under professors from the University of Iowa and Texas A&M University.